Fluorescent lamp fixtures take on various shapes and forms. Perhaps the most common of such fixtures is installed in a ceiling and includes at least a pair of elongated fluorescent lamps arranged in parallel. Other fluorescent lamp fixtures are of the portable type for temporary use in various indoor environments ranging from construction sites to industrial plants and office spaces. Portable fluorescent lamp fixtures are typically suspended overhead and may be coupled together in series to illuminate large areas.
One such prior art portable fluorescent lamp fixture 10 is shown in the exploded perspective view of FIG. 1. The fluorescent lamp fixture 10 includes a generally rectangular, planar frame 12 typically comprised of sheet metal to which are attached first and second pairs of lamp holders 14 and 16. First and second fluorescent lamps 18 and 20 are coupled to and supported by first and second pairs of lamp holders 14, 16 on the lower surface of the frame 12 which also serves as a fixed reflector. One or more ballasts 26, 28 are also typically attached to the lower surface of the frame 12. Ballasts 26, 28 are coupled to other lamp fixture circuitry attached to an upper surface of the frame 12 and not shown in the figure. An elongated, linear channel 22 attached to an upper surface of the frame 12 by means of mounting screws 24 typically encloses and covers the lamp fixture circuitry and wiring disposed on the upper surface of the frame. Frame 12, the fluorescent lamps 18, 20 and lamp fixture circuitry attached to the frame are inserted in a tube-like elongated transparent housing 44 for protecting the fluorescent lamps and for serving as a lens for light emitted by the lamps. First and second end caps 32 and 34 are securely attached to respective ends of housing 44 and frame 12 by means of a combination of threaded studs 36a and 36b on the ends of the frame and nylon cap nut and washer combinations 38a and 38b.
The prior art fluorescent lamp fixture 10 shown in FIG. 1 has various limitations. For example, an electrical lead such as a power cord 42 coupled to the fluorescent lamp fixture 10 at one of its end caps 34 is hard wired to lamp circuitry on frame 12. Cord 42 is maintained in position in end cap 34 by means of a compression nut 48 and a grommet (not shown). In order to repair or replace components within the fluorescent lamp fixture 10 or to replace a fluorescent lamp, compression nut 48 and the grommet must first be removed, allowing the second end cap 34 to be slid down cable 42 for providing access to the wire connections within the fixture. It is difficult and time consuming to remove the grommet from a tapered aperture within end cap 34. The nylon cap nuts and washers 38a and 38b must then be removed to allow removal of the second end cap 34 from the fluorescent lamp fixture 10. Frame 12 and the first and second fluorescent lamps 18, 20 must then be withdrawn from one end of tubular housing 44. This procedure is not only time consuming and cumbersome, but also requires a support surface on the order of twice the length of the fluorescent lamp fixture 10, which may be as long as four feet in length. In addition, channel 22 must be removed by removing the various mounting screws 24 to gain access to circuitry and wiring on the upper surface of frame 12 for repairing or replacing components disposed on the upper surface of the frame. Lamp fixture maintenance and repair is made more difficult by the positioning of circuitry and wiring on both sides of frame 12. Finally, cord 42 is subject to frequent damage in the rough-handling environment to which portable fluorescent lamps fixtures are accustomed. The cord's outer insulating sheath is frequently damaged, or the cord itself may be severed, when impacted by an edge of an end cap which frequently occurs when the fluorescent lamp fixture 10 is dropped. The rough-handling environment of a temporary installation typically encountered by portable fluorescent lamp fixtures thus places severe demands upon the fluorescent lamp fixture.